The episode begins with Ichabod, Abbie, Jenny and Nick out at a bar relaxing and doing karaoke. Nick gets a text and says he has a lead on some rare throwing stars and he will be back soon. He goes to meet a man named McKenna but ends up meeting a woman from his past named Carmilla Pines. She says that she needs his help and he immediately refuses. She asks if this how he should treat the woman who “raised him.” She plans to rob Theodore Knox’s estate and that he owes her.
Jenny talks with Abbie and wants to make sure things between her and Ichabod are good. She is also concerned that Nick hasn’t responded back to her yet. Abbie gets an alert that The Archives have been breached. They arrive there and find the place trashed and Jenny catches Nick fleeing the scene. Jenny chases him into the tunnels where he tells her to back off and is intercepted by Carmilla. She turns into a demon and lunges at Jenny but Ichabod shoots her in the chest with a crossbow. Carmilla vanishes and Abbie asks…”Who the hell was that?”
Captain Irving is sitting in court with his wife as his defense attorney. There is no charges against him so the judge exonerates all charges against him. He is happy to go home to his wife and child. Irving’s wife has an interesting look on her face.
In the Archives they discover that the creature had claws that contained acidic venom. Ichabod immediately realizes that it is a Batalla, an undead human being of Hindu law that serves Kali, the God of Death and Regeneration. They split up, Abbie and Jenny go looking for the dealer McKenna who set up Nick while Ichabod and Katrina search The Archives for clues where Nick is.
They arrive at McKenna’s shop where Jenny still questions Abbie’s relationship with Ichabod. McKenna claims to have no knowledge of anything but after some interrogation, he reveals the woman’s names is Carmilla Pines. Jenny knows her as a treasure hunter but also a killer. Meanwhile, Ichabod and Katrina browse through the mess in The Archives and Ichabod discovers an exact charm like one Orion gave to Abbie if she needed to summon him.
They find out that Carmilla was Nick’s legal guardian and she wants Nick because he has the blueprints to Fort Knox. Knox had an obsession with locks and puzzles so whatever is inside the vault is going to be very dangerous.
We see Nick showing Carmilla the layout of Fort Knox. He wants to know what happened to her after he ran away from her after witnessing her murder someone. She said she was captured by a death cult and they turned her into a Batalla. She claims an artifact in Fort Knox can help her reclaim her life. Nick says he will help her one last time.
Irving talks with his wife and she is having difficulty dealing with everything that has happened with him. She also tells him that Katrina might be able to help him.
They arrive at the Fort Knox Exchange and vow to stick together no matter what. They see Nick and Carmilla preparing to make their move on the vault. Jenny trails Nick while Ichabod and Abbie follow Carmilla. Nick figures out a way to access the vault through a puzzle behind a picture. Jenny confronts him and Nick says he will accept her help, then steals her phone and locks her out of the room, telling her to stay out of this.
Carmilla is now inside the vault and finds the artifact she is looking for. She picks it up right as Abbie shoots at her. Camilla grabs Abbie and holds her by the throat as Ichabod shows up with his crossbow drawn. He demands she be released and Carmilla threatens…”You shoot, she dies!”
Nick shows up to try and defuse the situation. Nick offers Carmilla a deal that he will leave with her and they lock them in the vault. Carmilla stole a statue of Kali used for a ceremony to turn humans into Batalla. Ichabod and Abbie begin to have a discussion in the vault about their current relationship while they try to escape.
Carmilla doesn’t believe Nick is being truthful and promises with the help of Kali, they will be together again. In the vault Ichabod and Abbie continue their discussion while he tries to figure out the puzzle. Ichabod thinks that their bond has been sorely tested and instead of figuring out the puzzle, triggers locking down the vault.
They are able to escape the vault when they meet up with Jenny and they go search for Nick. They trace him to an old warehouse and Ichabod visions the statue and they discover that they can kill Carmilla with iron and fire. Carmilla is preparing the ceremony for Nick and she comments to him “You will enjoy death Nicky!”
They arrive at the ceremony and demand Carmilla to back away from Nick. Abbie and Ichabod fight off and kill Carmilla’s men and go after Carmilla and Jenny knocks Carmilla away from Nick. Nick frees himself and threatens to kill her but Carmilla stalls him for a minute and is able to escape.
In The Archives Nick meets up with Jenny and tells her he is leaving to go hunt down Carmilla. Ichabod and Abbie are at the bar and talking about keeping their relationship strong and do a karaoke debut together.
Katrina performs a ceremony on Captain Irving at her cabin and finds out that whatever influence was on him is gone and that he is free. Henry is happy to start this new chapter of his life and hugs his wife. He also notices through the reflection in the window that he casts no shadow…